This invention relates to load control on electrical power distribution systems.
A utility supplying electrical power commonly has to exercise load management, that is to say, to effect some control over the power demand so that it does not exceed the supply capacity. Load management is exercised in a number of ways; for example the supply tariff for a particular consumer may include provisions regarding the maximum demand for power; as another example, certain loads on a consumer's premises may be connected on a circuit which is clock-controlled so that power is available only during certain periods of the day. More particularly with large consumers of electrical power, provision may be made for interruption of the supply to particular items of plant which have a high power consumption if the utility cannot meet the demand. In extreme circumstances, however, a utility may have to limit the demand by cutting off the supply to a number of consumers. This arises because there is no means, within the control of the utility, for limiting the demand of many of the individual consumers connected to the power supply network.
It will be noted that load control is effected in the first place by the provision of incentives and/or penalties to the consumer to encourage appropriate load management control. Load control by the utility is used only when load control by the consumer is insufficient.